PCI: Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems

Some Qualcomm PCIe devices (WCN6855/WCN7850 WiFi cards, SDX62/SDX65 modems)
do not properly support Secondary Bus Reset (SBR).

Testing confirms this is device-specific, not deployment-specific:
MediaTek MT7925e successfully uses bus reset through the same passive
M.2-to-PCIe adapters where Qualcomm devices fail, proving PERST# is
properly wired through the adapters.

Prevent use of Secondary Bus Reset for these devices.

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/all/20260609163649.319755-4-jtornosm@redhat.com

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index e49136ac5dbfb92e97695f9bed14a2312523d954..431c021d7414d21500f903a145c794bcbfb70a5a 100644 (file)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3790,6 +3790,9 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0033, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003e, quirk_no_bus_reset);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x1103, quirk_no_bus_reset); /* WCN6855 */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x1107, quirk_no_bus_reset); /* WCN7850 */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x0308, quirk_no_bus_reset); /* SDX62/SDX65 */
 
 /*
  * Root port on some Cavium CN8xxx chips do not successfully complete a bus